Morphological and electronic consequences of modifications to the polymer anode ??????PEDOT:PSS??????

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• 作者：Snaith ; Henry J. ; Kenrick ; Henry ; Chiesa ; Marco ; Friend ; Richard H.
• 关键词：PEDOT ; PSS ; Conducting polymers ; Organic optoelectronics
• 刊名：Polymer
• 出版年：2005
• 出版时间：March 24, 2005
• 年：2005
• 卷：46
• 期：8
• 页码：2573-2578
• 全文大小：526 K

文摘

We present a microscopic and electronic investigation of the polymeric anode poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) used as an electrode in photovoltaic and single carrier diodes. PEDOT:PSS is processed from aqueous solution as a colloidal dispersion with excess PSS present. We modify the PEDOT:PSS solution by the addition of a high boiling point alcohol, glycerol, which is known to increase the conductivity of the spin-coated film. Atomic force microscopy indicates swelling and greater aggregation of the PEDOT-rich colloidal particles found in this system. Current–voltage characteristics of ‘hole-transporting’ diodes, formed with gold contacts, suggest less surface enrichment of PSS in the glycerol modified electrode. Through Kelvin probe microscopy, we find the surface potential of glycerol modified PEDOT:PSS decreases by approximately 0.12 eV, which we assign to a reduction in surface enrichment by PSS. Photovoltaic diodes, using a PFB:F8BT polymer blend as the photo-active layer, and glycerol modified PEDOT:PSS anodes are significantly improved as compared to those with unmodified PEDOT:PSS anodes. This is likely to be due to improved hole-injection from the active polymer film into the PEDOT:PSS anode. This emphasises the electronic consequences of the morphological reorientation of the PEDOT and PSS.